MG Sports Cars

I have seen Jim's car, is not only the wide body but also the well engineered sub frame and back bone in the center that stiffens the car.
Jim also put the correct angle of the upper A arms to control anti dive which is the same as the C4 Vette.

There is much more than just wide body, impressive work. I can't wit until the day is done, I get to drink Jack Daniels upon completion of Jim's car, if the offer still on the table.

We could ride together to Colorado Jim if I finish my wide track GT. It would be hard to see what is ahead if I follow

The offer still stands. A friend of mine is going along in his Cobra coupe and the wives are going in comfort in a 993 Porsche.

Hello Gents...
I know I am resurrecting a pretty old thread but wanted to see if anyone who may understand MGB's better than I, and the nuances of the instructions, could help me clear up the trunk area.
Jim did a great job, I just think I'm a little too unfamiliar with the structural components to have a clear understanding of the last few steps in the trunk.
I thought the easiest way to communicate was to snap a few pictures and mark them up best I can. I am still tearing it down and haven't stripped the body of paint, rust and seam sealer yet.
Where I struggle is at the back of the trunk (boot) area. I get the benefit of separating at the mid point of the wheel wells that would allow wider rear wheels and tires.
I have questions in the content of the pictures themselves and should probably just let them speak for me.
Thanks for any guidance. - Mike

First, what is your overall plan? What engine/trans are you planning to use. What front suspension? How much do you plan on widening the car? What rear suspension are you going to use and how are you going to transmit the forces into the structure of the car? How are you going to reinforce the structure?
I have been on vacation in Cancun so I apologize for the delay answering.

I'm not sure I understand what you are asking. What you should end up with is the monocoque in 3 pieces - the trunk floor and bulkhead with the inner halves of the rear wheel wells attached and two body sides with the outer halves of the rear wheel wells attached. Actually, there is a 4th piece which is the trunk latch and license plate section. At that point you should be able to slide the body sides laterally to create the desired width with the trunk floor section remaining in place on centerline. You might find it easier to remove the trunk floor outboard of the frame rail and behind the wheel well and fabricate new pieces once the body is put back together. By removing that portion of the floor the cut in the wheel well will go all the way to the opening you just made and the rear cut in the center of the trunk area will end after you cut through the frame rail into the opening.

Before you raise a Sawzall in anger you really need to have the car in a fixture. If the parts are not held in proper relationship with one another, it will be almost impossible to put them back together in proper alignment. When I made my final cut to separate the two halves the pieces did not move at all relative to each other. Once you have slid the outer pieces outward to the desired width, the gaps you need to fill with new sheetmetal will become obvious.

Good luck.

Vacation in Cancun. Nice...I appreciate the interest. I'm committed but, yes, too little information in my original post.

Scope (in order of your great questions):
1. Overall plan...A cruiser, a hot rod MGB, something different, maybe even willing to incorporate very non-conventional solution ("Duvall-esque" winshield, Bop-top, etc..
2. I have a 4.8LS ready to be refreshed in February (builder is busy). Boost it, turbo. LS platform responds well.so a single GT45 or twin GT35's. Torque cam (BT Torque cam), street able, AC, nice interior, etc... I want my wife to ride with me (support the habit). I want to drive it in local SE USA trips.
3. 4L80 (turbos will smoke the 4L60's) although I'm not overly aggressive. This is mostly street (a little track)
4. Here's where I'm not sure a pure split wouldn't make more sense. I'm good with a traditional M2 IFS. 60" track with a matching Foxbody 8.8 on a parallel 4 - link. Mini tub the rear wells. So, maybe I need to think a full frame welded in, maybe delete the front frame and tube it ( with fender mount points) and teh full frame. I can jig and build it.
5. Reinforcement... tube.

So, I am generally thinking a welded in frame to transmit forces. I know at this point the shell is over built. Sills are typical. I would leave them as is. A full chassis would include sill support.

I now struggle with the thought of channeling a frame (problematic) or creating a full perimeter frame (2x4) with tube support under the floorpans.

Tell me I'm crazy. That 10" to 12" width would help plumbing the hot and cold side of those turbos.

Thanks for listening!
Mike.

Completely agree on having the car in a fixture on a dead flat and planar reference table. Fixtures and skids on each half so that can slide perfectly apart with no fore and aft misalignment or Z axis change.

You should check with Chuck Royer, Slightly Modified over on the Experience. He has a full frame incorporated in a standard width car with a high HP engine so could provide you with some guidance. The 11" width increase does certainly help with the plumbing and worked out just right with the Corvette 60" track. Also allowed easily fitting a 31" wide radiator for better cooling. Like you said, the MGB has a pretty rigid monocoque structure especially through the sills so I chose to add the extra rigidity with a backbone tunnel Lotus Elan style - the car is very rigid. I am also fairly tall so I wanted the floors as low as possible in the car so I could sit as low as possible. The floors are attached to the lowest point of the pinch weld giving the car a very flat bottom with the exhaust tucked up inside the tunnel so it doesn't drag. Probably one of the reasons it doesn't feel light at 130 mph ( the fastest I have gone not the top speed of the car).

Be sure to start journal on this site to document your build.

Will do. Thanks for the advice and guidance. I just have to say what an inspiration and how clean your build is. I keep going back to it. I will reach out to Mr Royer. I completely agree with you about keeping the seats low. I'm 6'0" but most of that in torso, not legs, think mountain gorilla.

I'll also document on the forum and not just lock up the photos in my phone.

My thoughts on the frame would be to basically build something similar to what Scott's builds (see attached). The perimeter frame would structurally replace the sills. When I bought this the owner put it on his lift. I poked and it looked great. i thought, "what a little peach I've found!". I pulled the fenders and the outer rocker at least on the passenger side has been replaced and I don't think it was perfect (door gap looks fine but fender alignment looks wrong). They also only tied the A pillar back to the sill inside the door jamb. Horrible tie back and I'll document booger welds and all found. Driver side has rot hidden under the fender and the outer sill and diaphragm at least are shot. Inner sills look great. My hope would be to fully frame it with the perimeter frame replacing the diaphragm and castle rail and tubing frame with a chassis X member under the pans which are perfect. I haven't measured the top of inner sill to floor pan to see if there is an inch hanging down of a 2"x4" frame (tucked in the inner sill) for the1"x2"(or 3") rectangular tubing cross member frame to tie under the car like a basket. Anyway, just thinking out loud.

I really like how you tucked the exhaust up into the transmission tunnel. Dumb question... Any issues with heat soak on the transmission? I'm with you in that I don't want to drag my exhaust.

Thanks again. The car is nearly stripped (no sense documenting that) so I'll start a project journal to expose all my inadequacies :)

I don't have any temp sensors in the trans but I don't seem to have any issues with heat soak. If you look at how I built the tunnel/backbone structure I built the framework out of 1" tubing and sheeted it on both sides with 18 ga steel and sandwiched some 1" urethane foam insulation in the middle. Before I had the carpeting in I could drive the car barefoot and the tunnel was just slightly warm and the exhaust was right on the other side. You will need to make the tunnel wider than mine if you want to fit the exhaust along side of a 4L80 trans but you will still have plenty of room inside. I have considered an automatic in mine but not sure I have the appetite for major surgery on the car at this point. The third pedal is my theft deterrent because nobody knows how to drive a stick anymore.

I was fortunate with my car that I have owned it since it was a 5 year old California car and there has never been any rust in the car at all. It was a shame that I had to throw all that pristine MGB metal away when I was building the car this time.

Hey Jim,
I just saw this post! In a way, I wish I would have seen it before I cut it but it all worked out. I had thought about following a method similar to what you laid out but ended up cutting it right down the middle.
Cheers,
Bill

This just reappeared after 8 years and I had forgotten about it or I would have pointed you to it when I heard you were cutting up yours.

Hello Jim and Jim,

I was thinking about a a couple of different approaches and I'd like your opinions.

1) I am thinking of sectioning the front fenders. First I'd section between the hood and the fender curve about an inch. Then I'd section on the other side of the fender curve another inch, similar to the two Volkswagen pictures I've attached. I would then increase the thickness of the door about two inches--I'm thinking of welding another door panel over the original one to make for a bit more side impact strength. I'd also add rocker panel extensions, using rocker panel patch panels. I am thinking this *might* give me some more space for a side exit exhaust in front of the rear wheel well. Finally, I would cut the rear fender panel and bring it out to line up with the wider door, tapering back toward the existing taillights and valance.

2) A similar approach to the front fenders (still with a 1" section between the hood and the fender curve), except instead of sectioning the fender on the outside of the fender curve, I'd slice the fender in line with the headlight (or just outside the headlight) and grow the width of the opening from nothing at the headlight to about an inch at the end of the fender. Then, instead of making the door two inches thicker, I'd taper the door thickness, from nothing at the front to two inches at the back of the door--and do the same with the rocker extensions. The idea here it to have a rear opening to the front fenders, similar to the 928 pictures I've attached.

What are your thoughts on either of these ideas?

Thanks much!

Eric

I think I would cut the fender along the edge of the hood like the top picture and leave the back portion open like on the 928. That way you preserve the arched top of the fender and the fill piece is just flat stock. You also don't have to mess with the doors and sills as much. If you have extra fenders I would leave a few inches of the rear portion in the stock location so the front edge of the door fits under the fender and the step down is covered.

Reminds me of IMSA style fenders, a look I really like 👍

I agree Phil. The rear fenders would require some widening as well if he does the fronts. An open-ended box might look appropriate and would be relatively easy to pull off. Maybe a more subtle version of this

Great input Jim. Thanks. How much of an opening at the back of the front fender do you think would be needed to look correct?

And Phil, yes. Apparently the 928 was also inspired by the IMSA fender idea. I just seems to me that this is a much easier way to widen the fenders than a bunch of compound flaring--or worse, having to use fiberglass, which I'm trying to avoid.

Also Jim,

Can you explain what you mean by "If you have extra fenders I would leave a few inches of the rear portion in the stock location so the front edge of the door fits under the fender and the step down is covered."

Get some chip board and tape it on the car until you are happy with what it looks like. If you are adding 1" of width at the hood line then your fender will be sticking out 1" at the door.

"If you have extra fenders I would leave a few inches of the rear portion in the stock location so the front edge of the door fits under the fender and the step down is covered."

I mis-stated, sorry. The rear edge of the fender has a step down that the front edge of the door covers when it is closed. By having a few inches of the original fender still in place, the opening created by the outer fender will have a finished look on the inside with the section of fender in place instead of seeing the kick panel of the cockpit. The outer fender will have the step down that will need to be addressed to create a finished look.

Jim,

Thanks, yes makes sense. I have a couple extra fenders that will be useful for that. And yes, have to figure out how to fill that step down on the exposed fender edge, but I did notice that.